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Ganchala D, Pinto-Benito D, Baides E, Ruiz-Palmero I, Grassi D, Arevalo MA. Kif21B mediates the effect of estradiol on the morphological plasticity of mouse hippocampal neurons. Front Mol Neurosci 2023; 16:1143024. [PMID: 37078090 PMCID: PMC10106616 DOI: 10.3389/fnmol.2023.1143024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/16/2023] [Indexed: 04/05/2023] Open
Abstract
IntroductionNeurons are polarized cells, and their ability to change their morphology has a functional implication in the development and plasticity of the nervous system in order to establish new connections. Extracellular factors strongly influence neuronal shape and connectivity. For instance, the developmental actions of estradiol on hippocampal neurons are well characterized, and we have demonstrated in previous studies that Ngn3 mediates these actions. On the other hand, Kif21B regulates microtubule dynamics and carries out retrograde transport of the TrkB/brain-derived neurotrophic factor (BDNF) complex, essential for neuronal development.MethodsIn the present study, we assessed the involvement of kinesin Kif21B in the estradiol-dependent signaling mechanisms to regulate neuritogenesis through cultured mouse hippocampal neurons.ResultsWe show that estradiol treatment increases BDNF expression, and estradiol and BDNF modify neuron morphology through TrkB signaling. Treatment with K252a, a TrkB inhibitor, decreases dendrite branching without affecting axonal length, whereas. Combined with estradiol or BDNF, it blocks their effects on axons but not dendrites. Notably, the downregulation of Kif21B abolishes the actions of estradiol and BDNF in both the axon and dendrites. In addition, Kif21B silencing also decreases Ngn3 expression, and downregulation of Ngn3 blocks the effect of BDNF on neuron morphology.DiscussionThese results suggest that Kif21B is required for the effects of estradiol and BDNF on neuronal morphology, but phosphorylation-mediated activation of TrkB is essential only for axonal growth. Our results show that the Estradiol/BDNF/TrkB/Kif21B/Ngn3 is a new and essential pathway mediating hippocampal neuron development.
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Affiliation(s)
| | - Daniel Pinto-Benito
- Instituto Cajal (IC), CSIC, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Isabel Ruiz-Palmero
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- Servicio de Proteómica, Instituto Biosanitario de Granada-IBS, Fundación Para la Investigación Biosanitaria de Andalucía Oriental—Alejandro Otero (FIBAO), Antiguo Hospital Universitario San Cecilio, Unidad de Apoyo a la Investigación (UNAI), Granada, Spain
| | - Daniela Grassi
- Instituto Cajal (IC), CSIC, Madrid, Spain
- Department of Anatomy, Histology and Neuroscience, Autonoma University of Madrid, Madrid, Spain
| | - Maria Angeles Arevalo
- Instituto Cajal (IC), CSIC, Madrid, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
- *Correspondence: Maria Angeles Arevalo,
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Bazzari AH, Bazzari FH. BDNF Therapeutic Mechanisms in Neuropsychiatric Disorders. Int J Mol Sci 2022; 23:ijms23158417. [PMID: 35955546 PMCID: PMC9368938 DOI: 10.3390/ijms23158417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 11/16/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is the most abundant neurotrophin in the adult brain and functions as both a primary neurotrophic signal and a neuromodulator. It serves essential roles in neuronal development, maintenance, transmission, and plasticity, thereby influencing aging, cognition, and behavior. Accumulating evidence associates reduced central and peripheral BDNF levels with various neuropsychiatric disorders, supporting its potential utilization as a biomarker of central pathologies. Subsequently, extensive research has been conducted to evaluate restoring, or otherwise augmenting, BDNF transmission as a potential therapeutic approach. Promising results were indeed observed for genetic BDNF upregulation or exogenous administration using a multitude of murine models of neurological and psychiatric diseases. However, varying mechanisms have been proposed to underlie the observed therapeutic effects, and many findings indicate the engagement of disease-specific and other non-specific mechanisms. This is because BDNF essentially affects all aspects of neuronal cellular function through tropomyosin receptor kinase B (TrkB) receptor signaling, the disruptions of which vary between brain regions across different pathologies leading to diversified consequences on cognition and behavior. Herein, we review the neurophysiology of BDNF transmission and signaling and classify the converging and diverging molecular mechanisms underlying its therapeutic potentials in neuropsychiatric disorders. These include neuroprotection, synaptic maintenance, immunomodulation, plasticity facilitation, secondary neuromodulation, and preservation of neurovascular unit integrity and cellular viability. Lastly, we discuss several findings suggesting BDNF as a common mediator of the therapeutic actions of centrally acting pharmacological agents used in the treatment of neurological and psychiatric illness.
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Affiliation(s)
- Amjad H. Bazzari
- Faculty of Medicine, Arab American University, 13 Zababdeh, Jenin 240, Palestine
- Correspondence:
| | - Firas H. Bazzari
- Faculty of Pharmacy, Arab American University, 13 Zababdeh, Jenin 240, Palestine;
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3
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Zavalin K, Hassan A, Fu C, Delpire E, Lagrange AH. Loss of KCC2 in GABAergic Neurons Causes Seizures and an Imbalance of Cortical Interneurons. Front Mol Neurosci 2022; 15:826427. [PMID: 35370549 PMCID: PMC8966887 DOI: 10.3389/fnmol.2022.826427] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 02/21/2022] [Indexed: 11/24/2022] Open
Abstract
K-Cl transporter KCC2 is an important regulator of neuronal development and neuronal function at maturity. Through its canonical transporter role, KCC2 maintains inhibitory responses mediated by γ-aminobutyric acid (GABA) type A receptors. During development, late onset of KCC2 transporter activity defines the period when depolarizing GABAergic signals promote a wealth of developmental processes. In addition to its transporter function, KCC2 directly interacts with a number of proteins to regulate dendritic spine formation, cell survival, synaptic plasticity, neuronal excitability, and other processes. Either overexpression or loss of KCC2 can lead to abnormal circuit formation, seizures, or even perinatal death. GABA has been reported to be especially important for driving migration and development of cortical interneurons (IN), and we hypothesized that properly timed onset of KCC2 expression is vital to this process. To test this hypothesis, we created a mouse with conditional knockout of KCC2 in Dlx5-lineage neurons (Dlx5 KCC2 cKO), which targets INs and other post-mitotic GABAergic neurons in the forebrain starting during embryonic development. While KCC2 was first expressed in the INs of layer 5 cortex, perinatal IN migrations and laminar localization appeared to be unaffected by the loss of KCC2. Nonetheless, the mice had early seizures, failure to thrive, and premature death in the second and third weeks of life. At this age, we found an underlying change in IN distribution, including an excess number of somatostatin neurons in layer 5 and a decrease in parvalbumin-expressing neurons in layer 2/3 and layer 6. Our research suggests that while KCC2 expression may not be entirely necessary for early IN migration, loss of KCC2 causes an imbalance in cortical interneuron subtypes, seizures, and early death. More work will be needed to define the specific cellular basis for these findings, including whether they are due to abnormal circuit formation versus the sequela of defective IN inhibition.
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Affiliation(s)
- Kirill Zavalin
- Department of Neurology, School of Medicine, Vanderbilt University, Nashville, TN, United States
| | - Anjana Hassan
- Department of Neurology, School of Medicine, Vanderbilt University, Nashville, TN, United States
| | - Cary Fu
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Eric Delpire
- Department of Anesthesiology, School of Medicine, Vanderbilt University, Nashville, TN, United States
| | - Andre H. Lagrange
- Department of Neurology, School of Medicine, Vanderbilt University, Nashville, TN, United States,Department of Neurology, Tennessee Valley Healthcare – Veterans Affairs (TVH VA), Medical Center, Nashville, TN, United States,*Correspondence: Andre H. Lagrange,
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4
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Chronic partial TrkB activation reduces seizures and mortality in a mouse model of Dravet syndrome. Proc Natl Acad Sci U S A 2022; 119:2022726119. [PMID: 35165147 PMCID: PMC8851461 DOI: 10.1073/pnas.2022726119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/29/2021] [Indexed: 12/03/2022] Open
Abstract
Dravet syndrome (DS) is a severe childhood epileptic encephalopathy characterized by intractable seizures and comorbidities, including a high rate of premature mortality. DS is mainly caused by loss-of-function mutations of the Scn1a gene encoding sodium channel Nav1.1 that is predominantly expressed in inhibitory parvalbumin-containing (PV) interneurons. Decreased Nav1.1 impairs PV cell function, causing DS phenotypes. Effective pharmacological therapy targeting defective PV interneurons is currently not available. This study demonstrated that early treatment with a partial TrkB receptor agonist, LM22A-4, increased Nav1.1 expression, improved PV interneuron function, and reduced seizure occurrence and mortality rate in DS mice, suggesting a potential therapy for DS. Dravet syndrome (DS) is one of the most severe childhood epilepsies, characterized by intractable seizures and comorbidities including cognitive and social dysfunction and high premature mortality. DS is mainly caused by loss-of-function mutations in the Scn1a gene encoding Nav1.1 that is predominantly expressed in inhibitory parvalbumin-containing (PV) interneurons. Decreased Nav1.1 impairs PV cell function, contributing to DS phenotypes. Effective pharmacological therapy that targets defective PV interneurons is not available. The known role of brain-derived neurotrophic factor (BDNF) in the development and maintenance of interneurons, together with our previous results showing improved PV interneuronal function and antiepileptogenic effects of a TrkB receptor agonist in a posttraumatic epilepsy model, led to the hypothesis that early treatment with a TrkB receptor agonist might prevent or reduce seizure activity in DS mice. To test this hypothesis, we treated DS mice with LM22A-4 (LM), a partial agonist at the BDNF TrkB receptor, for 7 d starting at postnatal day 13 (P13), before the onset of spontaneous seizures. Results from immunohistochemistry, Western blot, whole-cell patch-clamp recording, and in vivo seizure monitoring showed that LM treatment increased the number of perisomatic PV interneuronal synapses around cortical pyramidal cells in layer V, upregulated Nav1.1 in PV neurons, increased inhibitory synaptic transmission, and decreased seizures and the mortality rate in DS mice. The results suggest that early treatment with a partial TrkB receptor agonist may be a promising therapeutic approach to enhance PV interneuron function and reduce epileptogenesis and premature death in DS.
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5
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Lau CG, Zhang H, Murthy VN. Deletion of TrkB in parvalbumin interneurons alters cortical neural dynamics. J Cell Physiol 2021; 237:949-964. [PMID: 34491578 PMCID: PMC8810709 DOI: 10.1002/jcp.30571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 11/25/2022]
Abstract
Signaling by neurotrophins such as the brain‐derived neurotrophic factor (BDNF) is known to modulate development of interneurons, but the circuit effects of this modulation remain unclear. Here, we examined the impact of deleting TrkB, a BDNF receptor, in parvalbumin‐expressing (PV) interneurons on the balance of excitation and inhibition (E‐I) in cortical circuits. In the mouse olfactory cortex, TrkB deletion impairs multiple aspects of PV neuronal function including synaptic excitation, intrinsic excitability, and the innervation pattern of principal neurons. Impaired PV cell function resulted in aberrant spiking patterns in principal neurons in response to stimulation of sensory inputs. Surprisingly, dampened PV neuronal function leads to a paradoxical decrease in overall excitability in cortical circuits. Our study demonstrates that, by modulating PV circuit plasticity and development, TrkB plays a critical role in shaping the evoked pattern of activity in a cortical network.
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Affiliation(s)
- Chunyue Geoffrey Lau
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China.,Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA
| | - Huiqi Zhang
- Department of Neuroscience, City University of Hong Kong, Hong Kong, China
| | - Venkatesh N Murthy
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, Massachusetts, USA
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Neuregulins 1, 2, and 3 Promote Early Neurite Outgrowth in ErbB4-Expressing Cortical GABAergic Interneurons. Mol Neurobiol 2020; 57:3568-3588. [PMID: 32542595 DOI: 10.1007/s12035-020-01966-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/29/2020] [Indexed: 12/27/2022]
Abstract
The neuregulins (Nrgs 1-4) are a family of signaling molecules that play diverse roles in the nervous system. Nrg1 has been implicated in the formation of synapses and in synaptic plasticity. Previous studies have shown Nrg1 can affect neurite outgrowth in several neuronal populations, while the role of Nrg2 and Nrg3 in this process has remained understudied. The Nrgs can bind and activate the ErbB4 receptor tyrosine kinase which is preferentially expressed in GABAergic interneurons in the rodent hippocampus and cerebral cortex. In the present study, we evaluated the effects of Nrgs 1, 2, and 3 on neurite outgrowth of dissociated rat cortical ErbB4-positive (+)/GABA+ interneurons in vitro. All three Nrgs were able to promote neurite outgrowth during the first 2 days in vitro, with increases detected for both the axon (116-120%) and other neurites (100-120%). Increases in the average number of primary and secondary neurites were also observed. Treatment with the Nrgs for an additional 3 days promoted an increase in axonal length (86-96%), with only minimal effects on the remaining neurites (8-13%). ErbB4 expression persisted throughout the dendritic arbor and cell soma at all stages examined, while its expression in the axon was transient and declined with cell maturation. ErbB4 overexpression in GABAergic neurons promoted neurite outgrowth, an effect that was potentiated by Nrg treatment. These results show that Nrgs 1, 2, and 3 are each capable of influencing dendritic and axonal growth at early developmental stages in GABAergic neurons grown in vitro.
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7
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Gu F, Parada I, Yang T, Longo FM, Prince DA. Partial Activation of TrkB Receptors Corrects Interneuronal Calcium Channel Dysfunction and Reduces Epileptogenic Activity in Neocortex following Injury. Cereb Cortex 2020; 30:5180-5189. [PMID: 32488246 PMCID: PMC7391412 DOI: 10.1093/cercor/bhz254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 09/12/2019] [Accepted: 09/12/2019] [Indexed: 11/13/2022] Open
Abstract
Decreased GABAergic inhibition due to dysfunction of inhibitory interneurons plays an important role in post-traumatic epileptogenesis. Reduced N-current Ca2+ channel function in GABAergic terminals contributes to interneuronal abnormalities and neural circuit hyperexcitability in the partial neocortical isolation (undercut, UC) model of post-traumatic epileptogenesis. Because brain-derived neurotrophic factor (BDNF) supports the development and maintenance of interneurons, we hypothesized that the activation of BDNF tropomyosin kinase B (TrkB) receptors by a small molecule, TrkB partial agonist, PTX BD4-3 (BD), would correct N channel abnormalities and enhance inhibitory synaptic transmission in UC cortex. Immunocytochemistry (ICC) and western blots were used to quantify N- and P/Q-type channels. We recorded evoked (e)IPSCs and responses to N and P/Q channel blockers to determine the effects of BD on channel function. Field potential recordings were used to determine the effects of BD on circuit hyperexcitability. Chronic BD treatment 1) upregulated N and P/Q channel immunoreactivity in GABAergic terminals; 2) increased the effects of N or P/Q channel blockade on evoked inhibitory postsynaptic currents (eIPSCs); 3) increased GABA release probability and the frequency of sIPSCs; and 4) reduced the incidence of epileptiform discharges in UC cortex. The results suggest that chronic TrkB activation is a promising approach for rescuing injury-induced calcium channel abnormalities in inhibitory terminals, thereby improving interneuronal function and suppressing circuit hyperexcitability.
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Affiliation(s)
- Feng Gu
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - Isabel Parada
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - Tao Yang
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - Frank M Longo
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
| | - David A Prince
- Department of Neurology & Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305-5122, USA
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8
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Li C, Lei Y, Tian Y, Xu S, Shen X, Wu H, Bao S, Wang F. The etiological contribution of GABAergic plasticity to the pathogenesis of neuropathic pain. Mol Pain 2020; 15:1744806919847366. [PMID: 30977423 PMCID: PMC6509976 DOI: 10.1177/1744806919847366] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Neuropathic pain developing after peripheral or central nerve injury is the result of pathological changes generated through complex mechanisms. Disruption in the homeostasis of excitatory and inhibitory neurons within the central nervous system is a crucial factor in the formation of hyperalgesia or allodynia occurring with neuropathic pain. The central GABAergic pathway has received attention for its extensive distribution and function in neural circuits, including the generation and development of neuropathic pain. GABAergic inhibitory changes that occur in the interneurons along descending modulatory and nociceptive pathways in the central nervous system are believed to generate neuronal plasticity, such as synaptic plasticity or functional plasticity of the related genes or proteins, that is the foundation of persistent neuropathic pain. The primary GABAergic plasticity observed in neuropathic pain includes GABAergic synapse homo- and heterosynaptic plasticity, decreased synthesis of GABA, down-expression of glutamic acid decarboxylase and GABA transporter, abnormal expression of NKCC1 or KCC2, and disturbed function of GABA receptors. In this review, we describe possible mechanisms associated with GABAergic plasticity, such as central sensitization and GABAergic interneuron apoptosis, and the epigenetic etiologies of GABAergic plasticity in neuropathic pain. Moreover, we summarize potential therapeutic targets of GABAergic plasticity that may allow for successful relief of hyperalgesia from nerve injury. Finally, we compare the effects of the GABAergic system in neuropathic pain to other types of chronic pain to understand the contribution of GABAergic plasticity to neuropathic pain.
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Affiliation(s)
- Caijuan Li
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Yanying Lei
- 2 Department of Stomatology, Affiliated Hospital of Qinghai University, Xining, China
| | - Yi Tian
- 3 Department of Anesthesiology, Haikou Affiliated Hospital of Xiangya Medical School, Central South University, Haikou People's Hospital, Haikou, China
| | - Shiqin Xu
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Xiaofeng Shen
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Haibo Wu
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China
| | - Senzhu Bao
- 2 Department of Stomatology, Affiliated Hospital of Qinghai University, Xining, China
| | - Fuzhou Wang
- 1 Department of Anesthesiology, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, China.,4 Group of Neuropharmacology and Neurophysiology, Division of Neuroscience, The Bonoi Academy of Science and Education, Chapel Hill, NC, USA
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9
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O'Neill KM, Donohue KE, Omelchenko A, Firestein BL. The 3' UTRs of Brain-Derived Neurotrophic Factor Transcripts Differentially Regulate the Dendritic Arbor. Front Cell Neurosci 2018; 12:60. [PMID: 29563866 PMCID: PMC5845904 DOI: 10.3389/fncel.2018.00060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/19/2018] [Indexed: 12/13/2022] Open
Abstract
The patterning of dendrites is regulated by many factors, such as brain-derived neurotrophic factor (BDNF), which our laboratory has previously shown alters the dendritic arbor uniquely depending on the mode of extracellular application. In the current work, we examine how BDNF affects dendritogenesis in hippocampal neurons when it is overexpressed intracellularly by transcripts previously reported to be transported to distinct cellular compartments. The BDNF gene is processed at two different polyadenylation sites, leading to mRNA transcription with two different length 3′ untranslated regions (UTRs), and therefore, different mRNA localization preferences. We found that overexpression of BDNF mRNA with or without 3′ UTRs significantly alters dendritic branching compared to branching in control neurons as analyzed by Sholl distribution curves. Unexpectedly, we found that the overexpression of the shorter BDNF mRNA (reported to be preferentially targeted to the cell body) results in similar changes to Sholl curves compared to overexpression of the longer BDNF mRNA (reported to be preferentially targeted to both the cell body and dendrites). We also investigated whether the BDNF receptor TrkB mediates these changes and found that inhibiting TrkB blocks increases in Sholl curves, although at different distances depending on the transcript’s UTR. Finally, although it is not found in nature, we also examined the effects of overexpressing BDNF mRNA with the unique portion of the longer 3′ UTR since it was previously shown to be necessary for dendritic targeting of mRNA. We found that its overexpression increases Sholl curves at distances close to the cell body and that these changes also depend on TrkB activity. This work illustrates how the mRNA spatial code affects how BDNF alters local dendritogenesis and how TrkB may mediate these effects. Finally, our findings emphasize the importance of intracellular transport of BDNF mRNAs in the regulation of dendrite morphology.
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Affiliation(s)
- Kate M O'Neill
- Department of Cell Biology and Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States.,Graduate Program in Biomedical Engineering, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Katherine E Donohue
- Department of Cell Biology and Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States.,Graduate Program in Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States.,Biomedical Engineering Graduate Faculty, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States.,Neuroscience Graduate Faculty, Rutgers University, The State University of New Jersey, Piscataway, NJ, United States
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10
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André EM, Daviaud N, Sindji L, Cayon J, Perrot R, Montero-Menei CN. A novel ex vivo Huntington's disease model for studying GABAergic neurons and cell grafts by laser microdissection. PLoS One 2018; 13:e0193409. [PMID: 29505597 PMCID: PMC5837106 DOI: 10.1371/journal.pone.0193409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 02/09/2018] [Indexed: 02/05/2023] Open
Abstract
Organotypic brain slice cultures have been recently used to study neurodegenerative disorders such as Parkinson’s disease and Huntington’s disease (HD). They preserve brain three-dimensional architecture, synaptic connectivity and brain cells microenvironment. Here, we developed an innovative model of Huntington’s disease from coronal rat brain slices, that include all the areas involved in the pathology. HD-like neurodegeneration was obtained in only one week, in a single step, during organotypic slice preparation, without the use of neurotoxins. HD-like histopathology was analysed and after one week, a reduction of 40% of medium spiny neurons was observed. To analyse new therapeutic approaches in this innovative HD model, we developed a novel protocol of laser microdissection to isolate and analyse by RT-qPCR, grafted cells as well as surrounding tissue of fresh organotypic slices. We determined that laser microdissection could be performed on a 400μm organotypic slice after alcohol dehydration protocol, allowing the analysis of mRNA expression in the rat tissue as well as in grafted cells. In conclusion, we developed a new approach for modeling Huntington's disease ex vivo, and provided a useful innovative method for screening new potential therapies for neurodegenerative diseases especially when associated with laser microdissection.
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Affiliation(s)
- E. M. André
- CRCINA, INSERM, Université de Nantes, Université d’Angers, Angers, France
| | - N. Daviaud
- CRCINA, INSERM, Université de Nantes, Université d’Angers, Angers, France
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States of America
| | - L. Sindji
- CRCINA, INSERM, Université de Nantes, Université d’Angers, Angers, France
| | - J. Cayon
- PACEM, Angers University, Angers, France
| | - R. Perrot
- SCIAM, Angers University, Angers, France
| | - C. N. Montero-Menei
- CRCINA, INSERM, Université de Nantes, Université d’Angers, Angers, France
- * E-mail:
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Hing B, Sathyaputri L, Potash JB. A comprehensive review of genetic and epigenetic mechanisms that regulate BDNF expression and function with relevance to major depressive disorder. Am J Med Genet B Neuropsychiatr Genet 2018; 177:143-167. [PMID: 29243873 DOI: 10.1002/ajmg.b.32616] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 11/21/2017] [Indexed: 12/11/2022]
Abstract
Major depressive disorder (MDD) is a mood disorder that affects behavior and impairs cognition. A gene potentially important to this disorder is the brain derived neurotrophic factor (BDNF) as it is involved in processes controlling neuroplasticity. Various mechanisms exist to regulate BDNF's expression level, subcellular localization, and sorting to appropriate secretory pathways. Alterations to these processes by genetic factors and negative stressors can dysregulate its expression, with possible implications for MDD. Here, we review the mechanisms governing the regulation of BDNF expression, and discuss how disease-associated single nucleotide polymorphisms (SNPs) can alter these mechanisms, and influence MDD. As negative stressors increase the likelihood of MDD, we will also discuss the impact of these stressors on BDNF expression, the cellular effect of such a change, and its impact on behavior in animal models of stress. We will also describe epigenetic processes that mediate this change in BDNF expression. Similarities in BDNF expression between animal models of stress and those in MDD will be highlighted. We will also contrast epigenetic patterns at the BDNF locus between animal models of stress, and MDD patients, and address limitations to current clinical studies. Future work should focus on validating current genetic and epigenetic findings in tightly controlled clinical studies. Regions outside of BDNF promoters should also be explored, as should other epigenetic marks, to improve identification of biomarkers for MDD.
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Affiliation(s)
- Benjamin Hing
- Department of Psychiatry, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Leela Sathyaputri
- Department of Psychiatry, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - James B Potash
- Department of Psychiatry, Carver College of Medicine, University of Iowa, Iowa City, Iowa
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Gu F, Parada I, Yang T, Longo FM, Prince DA. Partial TrkB receptor activation suppresses cortical epileptogenesis through actions on parvalbumin interneurons. Neurobiol Dis 2018; 113:45-58. [PMID: 29408225 DOI: 10.1016/j.nbd.2018.01.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/21/2018] [Accepted: 01/24/2018] [Indexed: 01/17/2023] Open
Abstract
Post-traumatic epilepsy is one of the most common and difficult to treat forms of acquired epilepsy worldwide. Currently, there is no effective way to prevent post-traumatic epileptogenesis. It is known that abnormalities of interneurons, particularly parvalbumin-containing interneurons, play a critical role in epileptogenesis following traumatic brain injury. Thus, enhancing the function of existing parvalbumin interneurons might provide a logical therapeutic approach to prevention of post-traumatic epilepsy. The known positive effects of brain-derived neurotrophic factor on interneuronal growth and function through activation of its receptor tropomyosin receptor kinase B, and its decrease after traumatic brain injury, led us to hypothesize that enhancing trophic support might improve parvalbumin interneuronal function and decrease epileptogenesis. To test this hypothesis, we used the partial neocortical isolation ('undercut', UC) model of posttraumatic epileptogenesis in mature rats that were treated for 2 weeks, beginning on the day of injury, with LM22A-4, a newly designed partial agonist at the tropomyosin receptor kinase B. Effects of treatment were assessed with Western blots to measure pAKT/AKT; immunocytochemistry and whole cell patch clamp recordings to examine functional and structural properties of GABAergic interneurons; field potential recordings of epileptiform discharges in vitro; and video-EEG recordings of PTZ-induced seizures in vivo. Results showed that LM22A-4 treatment 1) increased pyramidal cell perisomatic immunoreactivity for VGAT, GAD65 and parvalbumin; 2) increased the density of close appositions of VGAT/gephyrin immunoreactive puncta (putative inhibitory synapses) on pyramidal cell somata; 3) increased the frequency of mIPSCs in pyramidal cells; and 4) decreased the incidence of spontaneous and evoked epileptiform discharges in vitro. 5) Treatment of rats with PTX BD4-3, another partial TrkB receptor agonist, reduced the incidence of bicuculline-induced ictal episodes in vitro and PTZ induced electrographic and behavioral ictal episodes in vivo. 6) Inactivation of TrkB receptors in undercut TrkBF616A mice with 1NMPP1 abolished both LM22A-4-induced effects on mIPSCs and on increased perisomatic VGAT-IR. Results indicate that chronic activation of the tropomyosin receptor kinase B by a partial agonist after cortical injury can enhance structural and functional measures of GABAergic inhibition and suppress posttraumatic epileptogenesis. Although the full agonist effects of brain-derived neurotrophic factor and tropomyosin receptor kinase B activation in epilepsy models have been controversial, the present results indicate that such trophic activation by a partial agonist may potentially serve as an effective therapeutic option for prophylactic treatment of posttraumatic epileptogenesis, and treatment of other neurological and psychiatric disorders whose pathogenesis involves impaired parvalbumin interneuronal function.
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Affiliation(s)
- Feng Gu
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - Isabel Parada
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States
| | - David A Prince
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, United States.
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Franchi SA, Macco R, Astro V, Tonoli D, Savino E, Valtorta F, Sala K, Botta M, de Curtis I. A Method to Culture GABAergic Interneurons Derived from the Medial Ganglionic Eminence. Front Cell Neurosci 2018; 11:423. [PMID: 29358905 PMCID: PMC5766683 DOI: 10.3389/fncel.2017.00423] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 12/18/2017] [Indexed: 11/13/2022] Open
Abstract
Understanding the mechanisms guiding interneuron development is a central aspect of the current research on cortical/hippocampal interneurons, which is highly relevant to brain function and pathology. In this methodological study we have addressed the setup of protocols for the reproducible culture of dissociated cells from murine medial ganglionic eminences (MGEs), to provide a culture system for the analysis of interneurons in vitro. This study includes the detailed protocols for the preparation of the dissociated cells, and for their culture on optimal substrates for cell migration or differentiation. These cultures enriched in interneurons may allow the investigation of the migratory behavior of interneuron precursors and their differentiation in vitro, up to the formation of morphologically identifiable GABAergic synapses. Live imaging of MGE-derived cells plated on proper substrates shows that they are useful to study the migratory behavior of the precursors, as well as the behavior of growth cones during the development of neurites. Most MGE-derived precursors develop into polarized GABAergic interneurons as determined by axonal, dendritic, and GABAergic markers. We present also a comparison of cells from WT and mutant mice as a proof of principle for the use of these cultures for the analysis of the migration and differentiation of GABAergic cells with different genetic backgrounds. The culture enriched in interneurons described here represents a useful experimental system to examine in a relatively easy and fast way the morpho-functional properties of these cells under physiological or pathological conditions, providing a powerful tool to complement the studies in vivo.
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Affiliation(s)
- Sira A Franchi
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Romina Macco
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Veronica Astro
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Diletta Tonoli
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Elisa Savino
- Neuropsychopharmacology Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Flavia Valtorta
- Neuropsychopharmacology Unit, Division of Neuroscience, San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Kristyna Sala
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Martina Botta
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
| | - Ivan de Curtis
- Cell Adhesion Unit San Raffaele Scientific Institute and San Raffaele University, Milan, Italy
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Gu F, Parada I, Shen F, Li J, Bacci A, Graber K, Taghavi RM, Scalise K, Schwartzkroin P, Wenzel J, Prince DA. Structural alterations in fast-spiking GABAergic interneurons in a model of posttraumatic neocortical epileptogenesis. Neurobiol Dis 2017; 108:100-114. [PMID: 28823934 DOI: 10.1016/j.nbd.2017.08.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 08/11/2017] [Accepted: 08/16/2017] [Indexed: 01/22/2023] Open
Abstract
Electrophysiological experiments in the partial cortical isolation ("undercut" or "UC") model of injury-induced neocortical epileptogenesis have shown alterations in GABAergic synaptic transmission attributable to abnormalities in presynaptic terminals. To determine whether the decreased inhibition was associated with structural abnormalities in GABAergic interneurons, we used immunocytochemical techniques, confocal microscopy and EM in UC and control sensorimotor rat cortex to analyze structural alterations in fast-spiking parvalbumin-containing interneurons and pyramidal (Pyr) cells of layer V. Principle findings were: 1) there were no decreases in counts of parvalbumin (PV)- or GABA-immunoreactive interneurons in UC cortex, however there were significant reductions in expression of VGAT and GAD-65 and -67 in halos of GABAergic terminals around Pyr somata in layer V. 2) Consistent with previous results, somatic size and density of Pyr cells was decreased in infragranular layers of UC cortex. 3) Dendrites of biocytin-filled FS interneurons were significantly decreased in volume. 4) There were decreases in the size and VGAT content of GABAergic boutons in axons of biocytin-filled FS cells in the UC, together with a decrease in colocalization with postsynaptic gephyrin, suggesting a reduction in GABAergic synapses. Quantitative EM of layer V Pyr somata confirmed the reduction in inhibitory synapses. 5) There were marked and lasting reductions in brain derived neurotrophic factor (BDNF)-IR and -mRNA in Pyr cells and decreased TrkB-IR on PV cells in UC cortex. 6) Results lead to the hypothesis that reduction in trophic support by BDNF derived from Pyr cells may contribute to the regressive changes in axonal terminals and dendrites of FS cells in the UC cortex and decreased GABAergic inhibition. SIGNIFICANCE Injury to cortical structures is a major cause of epilepsy, accounting for about 20% of cases in the general population, with an incidence as high as ~50% among brain-injured personnel in wartime. Loss of GABAergic inhibitory interneurons is a significant pathophysiological factor associated with epileptogenesis following brain trauma and other etiologies. Results of these experiments show that the largest population of cortical interneurons, the parvalbumin-containing fast-spiking (FS) interneurons, are preserved in the partial neocortical isolation model of partial epilepsy. However, axonal terminals of these cells are structurally abnormal, have decreased content of GABA synthetic enzymes and vesicular GABA transporter and make fewer synapses onto pyramidal neurons. These structural abnormalities underlie defects in GABAergic neurotransmission that are a key pathophysiological factor in epileptogenesis found in electrophysiological experiments. BDNF, and its TrkB receptor, key factors for maintenance of interneurons and pyramidal neurons, are decreased in the injured cortex. Results suggest that supplying BDNF to the injured epileptogenic brain may reverse the structural and functional abnormalities in the parvalbumin FS interneurons and provide an antiepileptogenic therapy.
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Affiliation(s)
- Feng Gu
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Isabel Parada
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Fran Shen
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Judith Li
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Alberto Bacci
- ICM - Hôpital Pitié Salpêtrière, 7, bd de l'hôpital, 75013 Paris, France
| | - Kevin Graber
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Reza Moein Taghavi
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Karina Scalise
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States
| | - Philip Schwartzkroin
- Department of Neurological Surgery, University of California, Davis, United States
| | - Jurgen Wenzel
- Department of Neurological Surgery, University of California, Davis, United States
| | - David A Prince
- Epilepsy Research Laboratories, Stanford Univ. Sch. of Medicine, United States.
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15
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Distinct effects on the dendritic arbor occur by microbead versus bath administration of brain-derived neurotrophic factor. Cell Mol Life Sci 2017; 74:4369-4385. [PMID: 28698933 DOI: 10.1007/s00018-017-2589-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 06/15/2017] [Accepted: 07/06/2017] [Indexed: 12/18/2022]
Abstract
Proper communication among neurons depends on an appropriately formed dendritic arbor, and thus, aberrant changes to the arbor are implicated in many pathologies, ranging from cognitive disorders to neurodegenerative diseases. Due to the importance of dendritic shape to neuronal network function, the morphology of dendrites is tightly controlled and is influenced by both intrinsic and extrinsic factors. In this work, we examine how brain-derived neurotrophic factor (BDNF), one of the most well-studied extrinsic regulators of dendritic branching, affects the arbor when it is applied locally via microbeads to cultures of hippocampal neurons. We found that local application of BDNF increases both proximal and distal branching in a time-dependent manner and that local BDNF application attenuates pruning of dendrites that occurs with neuronal maturation. Additionally, we examined whether cytosolic PSD-95 interactor (cypin), an intrinsic regulator of dendritic branching, plays a role in these changes and found strong evidence for the involvement of cypin in BDNF-promoted increases in dendrites after 24 but not 48 h of application. This current study extends our previous work in which we found that bath application of BDNF for 72 h, but not shorter times, increases proximal dendrite branching and that this increase occurs through transcriptional regulation of cypin. Moreover, this current work illustrates how dendritic branching is regulated differently by the same growth factor depending on its spatial localization, suggesting a novel pathway for modulation of dendritic branching locally.
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16
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Ohta KI, Suzuki S, Warita K, Kaji T, Kusaka T, Miki T. Prolonged maternal separation attenuates BDNF-ERK signaling correlated with spine formation in the hippocampus during early brain development. J Neurochem 2017; 141:179-194. [PMID: 28178750 DOI: 10.1111/jnc.13977] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 01/27/2017] [Accepted: 02/03/2017] [Indexed: 12/18/2022]
Abstract
Maternal separation (MS) is known to affect hippocampal function such as learning and memory, yet the molecular mechanism remains unknown. We hypothesized that these impairments are attributed to abnormities of neural circuit formation by MS, and focused on brain-derived neurotrophic factor (BDNF) as key factor because BDNF signaling has an essential role in synapse formation during early brain development. Using rat offspring exposed to MS for 6 h/day during postnatal days (PD) 2-20, we estimated BDNF signaling in the hippocampus during brain development. Our results show that MS attenuated BDNF expression and activation of extracellular signal-regulated kinase (ERK) around PD 7. Moreover, plasticity-related immediate early genes, which are transcriptionally regulated by BDNF-ERK signaling, were also reduced by MS around PD 7. Interestingly, detailed analysis revealed that MS particularly reduced expression of BDNF gene and immediate early genes in the cornu ammonis 1 (CA1) of hippocampus at PD 7. Considering that BDNF-ERK signaling is involved in spine formation, we next evaluated spine formation in the hippocampus during the weaning period. Our results show that MS particularly reduced mature spine density in proximal apical dendrites of CA1 pyramidal neurons at PD 21. These results suggest that MS could attenuate BDNF-ERK signaling during primary synaptogenesis with a region-specific manner, which is likely to lead to decreased spine formation and maturation observed in the hippocampal CA1 region. It is speculated that this incomplete spine formation during early brain development has an influence on learning capabilities throughout adulthood.
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Affiliation(s)
- Ken-Ichi Ohta
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shingo Suzuki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Katsuhiko Warita
- Department of Veterinary Anatomy, Faculty of Agriculture, Tottori University, Tottori, Japan
| | - Tomohiro Kaji
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Kusaka
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takanori Miki
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
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17
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Parent C, Wen X, Dhir SK, Ryan R, Diorio J, Zhang TY. Maternal care associates with differences in morphological complexity in the medial preoptic area. Behav Brain Res 2017; 326:22-32. [PMID: 28259675 DOI: 10.1016/j.bbr.2017.02.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/10/2017] [Accepted: 02/28/2017] [Indexed: 10/20/2022]
Abstract
The medial preoptic area (MPOA) is implicated in the expression of maternal behavior including the frequency of pup licking/grooming (LG) in the rat. Cyclic adenosine monophosphate (cAMP) responsive element-binding protein (CREB) is a transcription factor that regulates the expression of many genes. We found that lactating rats that are more maternal towards their pups showing increased licking/grooming (i.e. high-LG mothers) had increased levels of phosphorylated CREB (pCREB) in the MPOA following a nursing bout and they displayed a reduced population of greater dendritic complexity index (DCI) neurons compared to less maternal rats showing decreased licking/grooming (i.e. low-LG mothers). CREB overexpression in MPOA neuronal cultures associated with a decrease in dendritic complexity and an increase in the expression of Rem2 and brain-derived neurotrophic factor (BDNF), genes implicated in dendritic pruning. While there were no differences in Rem2 expression in virgin high and low-LG female rats, Rem2 was significantly increased in the MPOA of high-LG compared to low-LG lactating rats. CREB activity in the MPOA associates with maternal behavior and reduced dendritic complexity possibly by increasing Rem2 expression.
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Affiliation(s)
- Carine Parent
- Sackler Program for Epigenetics and Developmental Psychobiology at McGill University, Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Quebec H4H 1R3, Canada
| | - Xianglan Wen
- Sackler Program for Epigenetics and Developmental Psychobiology at McGill University, Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Quebec H4H 1R3, Canada
| | - Sabine K Dhir
- Sackler Program for Epigenetics and Developmental Psychobiology at McGill University, Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Quebec H4H 1R3, Canada
| | - Richard Ryan
- Sackler Program for Epigenetics and Developmental Psychobiology at McGill University, Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Quebec H4H 1R3, Canada
| | - Josie Diorio
- Sackler Program for Epigenetics and Developmental Psychobiology at McGill University, Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Quebec H4H 1R3, Canada
| | - Tie-Yuan Zhang
- Sackler Program for Epigenetics and Developmental Psychobiology at McGill University, Ludmer Centre for Neuroinformatics and Mental Health, Douglas Mental Health University Institute, McGill University, Montreal, Quebec H4H 1R3, Canada; Department of Psychiatry, McGill University, Montreal, Quebec H3A 1A1, Canada.
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18
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Kim J, Lee S, Kang S, Kim SH, Kim JC, Yang M, Moon C. Brain-derived neurotropic factor and GABAergic transmission in neurodegeneration and neuroregeneration. Neural Regen Res 2017; 12:1733-1741. [PMID: 29171440 PMCID: PMC5696856 DOI: 10.4103/1673-5374.217353] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neurotoxicity induced by stress, radiation, chemicals, or metabolic diseases, is commonly associated with excitotoxicity, oxidative stress, and neuroinflammation. The pathological process of neurotoxicity induces neuronal death, interrupts synaptic plasticity in the brain, and is similar to that of diverse neurodegenerative diseases. Animal models of neurotoxicity have revealed that clinical symptoms and brain lesions can recover over time via neuroregenerative processes. Specifically, brain-derived neurotropic factor (BDNF) and gamma-aminobutyric acid (GABA)-ergic transmission are related to both neurodegeneration and neuroregeneration. This review summarizes the accumulating evidences that suggest a pathogenic role of BDNF and GABAergic transmission, their underlying mechanisms, and the relationship between BDNF and GABA in neurodegeneration and neuroregeneration. This review will provide a comprehensive overview of the underlying mechanisms of neuroregeneration that may help in developing potential strategies for pharmacotherapeutic approaches to treat neurotoxicity and neurodegenerative disease.
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Affiliation(s)
- Jinwook Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 PLUS Project Team, Chonnam National University, Gwangju, South Korea
| | - Sueun Lee
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 PLUS Project Team, Chonnam National University, Gwangju, South Korea
| | - Sohi Kang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 PLUS Project Team, Chonnam National University, Gwangju, South Korea
| | - Sung-Ho Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 PLUS Project Team, Chonnam National University, Gwangju, South Korea
| | - Jong-Choon Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 PLUS Project Team, Chonnam National University, Gwangju, South Korea
| | - Miyoung Yang
- Department of Anatomy, School of Medicine and Institute for Environmental Science, Wonkwang University, Jeonbuk, South Korea
| | - Changjong Moon
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 PLUS Project Team, Chonnam National University, Gwangju, South Korea
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19
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Oh H, Lewis DA, Sibille E. The Role of BDNF in Age-Dependent Changes of Excitatory and Inhibitory Synaptic Markers in the Human Prefrontal Cortex. Neuropsychopharmacology 2016; 41:3080-3091. [PMID: 27417517 PMCID: PMC5101556 DOI: 10.1038/npp.2016.126] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 06/10/2016] [Accepted: 07/04/2016] [Indexed: 01/07/2023]
Abstract
Reduced brain-derived neurotrophic factor (BDNF) may underlie age-related synaptic loss, in turn contributing to cerebral atrophy, cognitive decline, and increased risk for psychiatric disorders. However, the specific contribution of BDNF to the age-related expression changes in synaptic markers and their temporal trajectories remain uncharacterized. Using microarray data from orbitofrontal cortex of control subjects (n=209; 16-96 years), we identified genes whose expression positively correlates with BDNF (r>0.575; n=200 genes) and analyzed them for enriched biological pathways. qPCR was performed to measure the expression level of transcript variants of BDNF, NTRK2, and selected BDNF-coexpressed genes in younger and older subjects. We confirmed age-related downregulation of BDNF and show 78 of the top 200 BDNF-coexpressed genes are associated with synaptic function. Both excitatory and inhibitory synaptic genes show decreased expression with age and are positively correlated with BDNF and NTRK2 expression and negatively correlated with dominant-negative truncated NTRK2 level. Results were validated at the RNA level in an independent cohort and at the protein level for selected findings. We next tested the causal link between the correlative human findings using mice with conditional blockade of BDNF/NTRK2 signaling. Blockade of NTRK2 activity in adult mice recapitulate the age-like pattern in the expression of markers for inhibitory presynaptic but notably not for excitatory synaptic genes. Together, these findings suggest that age-dependent decrease in BDNF signaling may cause synaptic alterations through an initial and preferential effect on GABA presynaptic genes. These results have implications for neuropsychiatric disorders characterized by accelerated aging molecular profiles, such as major depression.
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Affiliation(s)
- Hyunjung Oh
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada
| | - David A Lewis
- Department of Psychiatry, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), Toronto, Ontario, Canada,Department of Psychiatry, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada,Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health (CAMH), 250 College Street, Room 134, Toronto, Ontario M5T 1R8, Canada, Tel: +1 416 535 8501, E-mail:
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Rahimian P, He JJ. HIV-1 Tat-shortened neurite outgrowth through regulation of microRNA-132 and its target gene expression. J Neuroinflammation 2016; 13:247. [PMID: 27634380 PMCID: PMC5025601 DOI: 10.1186/s12974-016-0716-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/08/2016] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Synaptodendritic damage is a pathological hallmark of HIV-associated neurocognitive disorders, and HIV-1 Tat protein is known to cause such injury in the central nervous system. In this study, we aimed to determine the molecular mechanisms of Tat-induced neurite shortening, specifically the roles of miR-132, an important regulator of neurite morphogenesis in this process. METHODS The relationship between Tat expression and miR-132 expression was first determined using reverse transcription quantitative PCR (qRT-PCR) in Tat-transfected astrocytes and neurons, astrocytes from Tat-transgenic mice, and HIV-infected astrocytes. qRT-PCR and Western blotting were performed to determine Tat effects on expression of miR-132 target genes methyl CpG-binding protein 2, Rho GTPase activator p250GAP, and brain-derived neurotrophic factor. Exosomes were isolated from Tat-expressing astrocytes, and exosomal microRNA (miRNA) uptake into neurons was studied using miRNA labeling and flow cytometry. The lactate dehydrogenase release was used to determine the cytotoxicity, while immunostaining was used to determine neurite lengths and synapse formation. Tat basic domain deletion mutant and miR-132 mimic and inhibitor were used to determine the specificity of the relationship between Tat and miR-132 and its effects on astrocytes and neurons and the underlying mechanisms of Tat-induced miR-132 expression. RESULTS Tat significantly induced miR-132 expression, ensuing down-regulation of miR-132 target genes in astrocytes and neurons. miR-132 induction was associated with phosphorylation of cAMP response element-binding protein and required the basic domain of Tat. miRNA-132 induction had no effects on astrocyte activation or survival but was involved in the direct neurotoxicity of Tat. miR-132 was present in astrocyte-derived exosomes and was taken up by neurons, causing neurite shortening. CONCLUSIONS Tat-induced miR-132 expression contributes to both direct and astrocyte-mediated Tat neurotoxicity and supports the important roles of miR-132 in controlling neurite outgrowth.
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Affiliation(s)
- Pejman Rahimian
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107 USA
| | - Johnny J. He
- Department of Cell Biology and Immunology, Graduate School of Biomedical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107 USA
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21
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Binley KE, Ng WS, Barde YA, Song B, Morgan JE. Brain-derived neurotrophic factor prevents dendritic retraction of adult mouse retinal ganglion cells. Eur J Neurosci 2016; 44:2028-39. [PMID: 27285957 PMCID: PMC4988502 DOI: 10.1111/ejn.13295] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 06/02/2016] [Accepted: 06/06/2016] [Indexed: 01/24/2023]
Abstract
We used cultured adult mouse retinae as a model system to follow and quantify the retraction of dendrites using diolistic labelling of retinal ganglion cells (RGCs) following explantation. Cell death was monitored in parallel by nuclear staining as ‘labelling’ with RGC and apoptotic markers was inconsistent and exceedingly difficult to quantify reliably. Nuclear staining allowed us to delineate a lengthy time window during which dendrite retraction can be monitored in the absence of RGC death. The addition of brain‐derived neurotrophic factor (BDNF) produced a marked reduction in dendritic degeneration, even when application was delayed for 3 days after retinal explantation. These results suggest that the delayed addition of trophic factors may be functionally beneficial before the loss of cell bodies in the course of conditions such as glaucoma.
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Affiliation(s)
- Kate E Binley
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Wai S Ng
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Yves-Alain Barde
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Cardiff, UK
| | - Bing Song
- School of Dentistry, Cardiff University, Heath Park, Cardiff, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ, UK
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22
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Bal-Price A, Lein PJ, Keil KP, Sethi S, Shafer T, Barenys M, Fritsche E, Sachana M, Meek MEB. Developing and applying the adverse outcome pathway concept for understanding and predicting neurotoxicity. Neurotoxicology 2016; 59:240-255. [PMID: 27212452 DOI: 10.1016/j.neuro.2016.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 05/13/2016] [Accepted: 05/13/2016] [Indexed: 12/12/2022]
Abstract
The Adverse Outcome Pathway (AOP) concept has recently been proposed to support a paradigm shift in regulatory toxicology testing and risk assessment. This concept is similar to the Mode of Action (MOA), in that it describes a sequence of measurable key events triggered by a molecular initiating event in which a stressor interacts with a biological target. The resulting cascade of key events includes molecular, cellular, structural and functional changes in biological systems, resulting in a measurable adverse outcome. Thereby, an AOP ideally provides information relevant to chemical structure-activity relationships as a basis for predicting effects of structurally similar compounds. AOPs could potentially also form the basis for qualitative and quantitative predictive modeling of the human adverse outcome resulting from molecular initiating or other key events for which higher-throughput testing methods are available or can be developed. A variety of cellular and molecular processes are known to be critical for normal function of the central (CNS) and peripheral nervous systems (PNS). Because of the biological and functional complexity of the CNS and PNS, it has been challenging to establish causative links and quantitative relationships between key events that comprise the pathways leading from chemical exposure to an adverse outcome in the nervous system. Following introduction of the principles of MOA and AOPs, examples of potential or putative adverse outcome pathways specific for developmental or adult neurotoxicity are summarized and aspects of their assessment considered. Their possible application in developing mechanistically informed Integrated Approaches to Testing and Assessment (IATA) is also discussed.
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Affiliation(s)
- Anna Bal-Price
- European Commission Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy.
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Kimberly P Keil
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Sunjay Sethi
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Timothy Shafer
- Integrated Systems Toxicology Division, Office of Research and Development, U.S. Environmental Protection Agency, RTP, USA
| | - Marta Barenys
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Ellen Fritsche
- IUF-Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Magdalini Sachana
- European Commission Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy
| | - M E Bette Meek
- McLaughlin Centre for Risk Science, University of Ottawa, Ottawa, Canada
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Alsina FC, Hita FJ, Fontanet PA, Irala D, Hedman H, Ledda F, Paratcha G. Lrig1 is a cell-intrinsic modulator of hippocampal dendrite complexity and BDNF signaling. EMBO Rep 2016; 17:601-16. [PMID: 26935556 DOI: 10.15252/embr.201541218] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 01/28/2016] [Indexed: 11/09/2022] Open
Abstract
Even though many extracellular factors have been identified as promoters of general dendritic growth and branching, little is known about the cell-intrinsic modulators that allow neurons to sculpt distinctive patterns of dendrite arborization. Here, we identify Lrig1, a nervous system-enriched LRR protein, as a key physiological regulator of dendrite complexity of hippocampal pyramidal neurons. Lrig1-deficient mice display morphological changes in proximal dendrite arborization and defects in social interaction. Specifically, knockdown of Lrig1 enhances both primary dendrite formation and proximal dendritic branching of hippocampal neurons, two phenotypes that resemble the effect of BDNF on these neurons. In addition, we show that Lrig1 physically interacts with TrkB and attenuates BDNF signaling. Gain and loss of function assays indicate that Lrig1 restricts BDNF-induced dendrite morphology. Together, our findings reveal a novel and essential role of Lrig1 in regulating morphogenic events that shape the hippocampal circuits and establish that the assembly of TrkB with Lrig1 represents a key mechanism for understanding how specific neuronal populations expand the repertoire of responses to BDNF during brain development.
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Affiliation(s)
- Fernando Cruz Alsina
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET School of Medicine University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Francisco Javier Hita
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET School of Medicine University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Paula Aldana Fontanet
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET School of Medicine University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Dolores Irala
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET School of Medicine University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Håkan Hedman
- Oncology Research Laboratory, Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - Fernanda Ledda
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET School of Medicine University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Gustavo Paratcha
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET School of Medicine University of Buenos Aires (UBA), Buenos Aires, Argentina
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Prince D, Gu F, Parada I. Antiepileptogenic repair of excitatory and inhibitory synaptic connectivity after neocortical trauma. PROGRESS IN BRAIN RESEARCH 2016; 226:209-27. [DOI: 10.1016/bs.pbr.2016.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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25
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Ehrlich DE, Josselyn SA. Plasticity-related genes in brain development and amygdala-dependent learning. GENES BRAIN AND BEHAVIOR 2015; 15:125-43. [PMID: 26419764 DOI: 10.1111/gbb.12255] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/12/2015] [Accepted: 09/14/2015] [Indexed: 12/31/2022]
Abstract
Learning about motivationally important stimuli involves plasticity in the amygdala, a temporal lobe structure. Amygdala-dependent learning involves a growing number of plasticity-related signaling pathways also implicated in brain development, suggesting that learning-related signaling in juveniles may simultaneously influence development. Here, we review the pleiotropic functions in nervous system development and amygdala-dependent learning of a signaling pathway that includes brain-derived neurotrophic factor (BDNF), extracellular signaling-related kinases (ERKs) and cyclic AMP-response element binding protein (CREB). Using these canonical, plasticity-related genes as an example, we discuss the intersection of learning-related and developmental plasticity in the immature amygdala, when aversive and appetitive learning may influence the developmental trajectory of amygdala function. We propose that learning-dependent activation of BDNF, ERK and CREB signaling in the immature amygdala exaggerates and accelerates neural development, promoting amygdala excitability and environmental sensitivity later in life.
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Affiliation(s)
- D E Ehrlich
- Department of Neuroscience and Physiology, Neuroscience Institute, NYU Langone Medical Center, New York, NY, USA.,Department of Otolaryngology, NYU Langone School of Medicine, New York, NY, USA
| | - S A Josselyn
- Program in Neurosciences & Mental Health, Hospital for Sick Children, Toronto, ON, Canada.,Department of Psychology, University of Toronto, Toronto, ON, Canada.,Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
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26
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McDole B, Isgor C, Pare C, Guthrie K. BDNF over-expression increases olfactory bulb granule cell dendritic spine density in vivo. Neuroscience 2015. [PMID: 26211445 DOI: 10.1016/j.neuroscience.2015.07.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Olfactory bulb granule cells (GCs) are axon-less, inhibitory interneurons that regulate the activity of the excitatory output neurons, the mitral and tufted cells, through reciprocal dendrodendritic synapses located on GC spines. These contacts are established in the distal apical dendritic compartment, while GC basal dendrites and more proximal apical segments bear spines that receive glutamatergic inputs from the olfactory cortices. This synaptic connectivity is vital to olfactory circuit function and is remodeled during development, and in response to changes in sensory activity and lifelong GC neurogenesis. Manipulations that alter levels of the neurotrophin brain-derived neurotrophic factor (BDNF) in vivo have significant effects on dendritic spine morphology, maintenance and activity-dependent plasticity for a variety of CNS neurons, yet little is known regarding BDNF effects on bulb GC spine maturation or maintenance. Here we show that, in vivo, sustained bulbar over-expression of BDNF in transgenic mice produces a marked increase in GC spine density that includes an increase in mature spines on their apical dendrites. Morphometric analysis demonstrated that changes in spine density were most notable in the distal and proximal apical domains, indicating that multiple excitatory inputs are potentially modified by BDNF. Our results indicate that increased levels of endogenous BDNF can promote the maturation and/or maintenance of dendritic spines on GCs, suggesting a role for this factor in modulating GC functional connectivity within adult olfactory circuitry.
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Affiliation(s)
- B McDole
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, United States
| | - C Isgor
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, United States
| | - C Pare
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, United States
| | - K Guthrie
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, United States.
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27
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Mattei G, Cristiani I, Magliaro C, Ahluwalia A. Profile analysis of hepatic porcine and murine brain tissue slices obtained with a vibratome. PeerJ 2015; 3:e932. [PMID: 25945319 PMCID: PMC4419543 DOI: 10.7717/peerj.932] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/14/2015] [Indexed: 11/28/2022] Open
Abstract
This study is aimed at characterizing soft tissue slices using a vibratome. In particular, the effect of two sectioning parameters (i.e., step size and sectioning speed) on resultant slice thickness was investigated for fresh porcine liver as well as for paraformaldehyde-fixed (PFA-fixed) and fresh murine brain. A simple framework for embedding, sectioning and imaging the slices was established to derive their thickness, which was evaluated through a purposely developed graphical user interface. Sectioning speed and step size had little effect on the thickness of fresh liver slices. Conversely, the thickness of PFA-fixed murine brain slices was found to be dependent on the step size, but not on the sectioning speed. In view of these results, fresh brain tissue was sliced varying the step size only, which was found to have a significant effect on resultant slice thickness. Although precision-cut slices (i.e., with regular thickness) were obtained for all the tissues, slice accuracy (defined as the match between the nominal step size chosen and the actual slice thickness obtained) was found to increase with tissue stiffness from fresh liver to PFA-fixed brain. This quantitative investigation can be very helpful for establishing the most suitable slicing setup for a given tissue.
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Affiliation(s)
- G Mattei
- Research Center "E. Piaggio," University of Pisa , Pisa , Italy
| | - I Cristiani
- Research Center "E. Piaggio," University of Pisa , Pisa , Italy
| | - C Magliaro
- Research Center "E. Piaggio," University of Pisa , Pisa , Italy
| | - A Ahluwalia
- Research Center "E. Piaggio," University of Pisa , Pisa , Italy ; Institute of Clinical Physiology, National Research Council , Pisa , Italy
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Godar SC, Bortolato M, Richards SE, Li FG, Chen K, Wellman CL, Shih JC. Monoamine Oxidase A is Required for Rapid Dendritic Remodeling in Response to Stress. Int J Neuropsychopharmacol 2015; 18:pyv035. [PMID: 25857821 PMCID: PMC4576521 DOI: 10.1093/ijnp/pyv035] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/16/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Acute stress triggers transient alterations in the synaptic release and metabolism of brain monoamine neurotransmitters. These rapid changes are essential to activate neuroplastic processes aimed at the appraisal of the stressor and enactment of commensurate defensive behaviors. Threat evaluation has been recently associated with the dendritic morphology of pyramidal cells in the orbitofrontal cortex (OFC) and basolateral amygdala (BLA); thus, we examined the rapid effects of restraint stress on anxiety-like behavior and dendritic morphology in the BLA and OFC of mice. Furthermore, we tested whether these processes may be affected by deficiency of monoamine oxidase A (MAO-A), the primary enzyme catalyzing monoamine metabolism. METHODS Following a short-term (1-4h) restraint schedule, MAO-A knockout (KO) and wild-type (WT) mice were sacrificed, and histological analyses of dendrites in pyramidal neurons of the BLA and OFC of the animals were performed. Anxiety-like behaviors were examined in a separate cohort of animals subjected to the same experimental conditions. RESULTS In WT mice, short-term restraint stress significantly enhanced anxiety-like responses, as well as a time-dependent proliferation of apical (but not basilar) dendrites of the OFC neurons; conversely, a retraction in BLA dendrites was observed. None of these behavioral and morphological changes were observed in MAO-A KO mice. CONCLUSIONS These findings suggest that acute stress induces anxiety-like responses by affecting rapid dendritic remodeling in the pyramidal cells of OFC and BLA; furthermore, our data show that MAO-A and monoamine metabolism are required for these phenomena.
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Affiliation(s)
| | | | | | | | | | | | - Jean C Shih
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA (Drs Godar, Chen, and Shih and Mr Li); Department of Cell and Neurobiology, University of Southern California, Los Angeles, CA (Dr Shih); Department of Pharmacology and Toxicology, University of Kansas, Lawrence, KS (Drs Godar and Bortolato); Consortium for Translational Research on Aggression and Drug Abuse (ConTRADA), University of Kansas, Lawrence, KS, (Drs Godar and Bortolato); Department of Psychological & Brain Sciences and Program in Neuroscience, Indiana University, Bloomington, IN (Ms Richards and Dr Wellman)
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29
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Jin P, Yu HL, Tian-Lan, Zhang F, Quan ZS. Antidepressant-like effects of oleoylethanolamide in a mouse model of chronic unpredictable mild stress. Pharmacol Biochem Behav 2015; 133:146-54. [PMID: 25864425 DOI: 10.1016/j.pbb.2015.04.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/30/2015] [Accepted: 04/03/2015] [Indexed: 12/22/2022]
Abstract
Oleoylethanolamide (OEA) is an endocannabinoid analog that belongs to a family of endogenous acylethanolamides. Increasing evidence suggests that OEA may act as an endogenous neuroprotective factor and participate in the control of mental disorder-related behaviors. In this study, we examined whether OEA is effective against depression and investigated the role of circulating endogenous acylethanolamides during stress. Mice were subjected to 28days of chronic unpredictable mild stress (CUMS), and during the last 21days, treated with oral OEA (1.5-6mg/kg) or 6mg/kg fluoxetine. Sucrose preference and open field test activity were used to evaluate depression-like behaviors during CUMS and after OEA treatment. Weights of the prefrontal cortex and hippocampus were determined, and the adrenal index was measured. Furthermore, changes in serum adrenocorticotropic hormone (ACTH), corticosterone (CORT) and total antioxidant capacity (T-AOC), brain-derived neurotrophic factor (BDNF), and lipid peroxidation product malondialdehyde (MDA) levels, and superoxide dismutase (SOD) activities in the hippocampus and prefrontal cortex were detected. Our findings indicate that OEA normalized sucrose preferences, locomotion distances, rearing frequencies, prefrontal cortex and hippocampal atrophy, and adrenal indices. In addition, OEA reversed the abnormalities of BDNF and MDA levels and SOD activities in the hippocampus and prefrontal cortex, as well as changes in serum levels of ACTH, CORT, and T-AOC. The antidepressant effects of OEA may be related to the regulation of BDNF levels in the hippocampus and prefrontal cortex, antioxidant defenses, and normalizing hyperactivity in the hypothalamic-pituitary-adrenal axis (HPA).
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Affiliation(s)
- Peng Jin
- Key Laboratory of Natural Resources and Functional Molecules of the Changbai Mountain, Affiliated Ministry of Education, Yanbian University College of Pharmacy, Yanji 133000, PR China; Department of Pharmacology, Ischemic/Hypoxic Disease Institute, Cancer Research Institute, College of Medicine, Seoul National University, Yongon-dong 28, Chongno-gu, Seoul 110-799, Republic of Korea; Department of Biomedical Science, Ischemic/Hypoxic Disease Institute, Cancer Research Institute, College of Medicine, Seoul National University, Yongon-dong 28, Chongno-gu, Seoul 110-799, Republic of Korea
| | - Hai-Ling Yu
- College of Medicine, Yanbian University, Park Street 977, Yanji, 133002 Jilin, PR China.
| | - Tian-Lan
- College of Medicine, Yanbian University, Park Street 977, Yanji, 133002 Jilin, PR China
| | - Feng Zhang
- College of Medicine, Yanbian University, Park Street 977, Yanji, 133002 Jilin, PR China
| | - Zhe-Shan Quan
- Key Laboratory of Natural Resources and Functional Molecules of the Changbai Mountain, Affiliated Ministry of Education, Yanbian University College of Pharmacy, Yanji 133000, PR China.
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ERV enhances spatial learning and prevents the development of infarcts, accompanied by upregulated BDNF in the cortex. Brain Res 2015; 1610:110-23. [PMID: 25842373 DOI: 10.1016/j.brainres.2015.03.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 03/19/2015] [Accepted: 03/24/2015] [Indexed: 01/18/2023]
Abstract
PURPOSES An anti-allergic and analgesic drug, "an extract derived from the inflamed cutaneous tissue of rabbits inoculated with vaccinia virus (ERV)", has been used in medical practice in Japan and some other countries. We examined the effect of ERV, prior to induction of ischemia, on the development of cerebral infarction, on learning and memory, or on brain-derived neurotrophic factor (BDNF) levels in C57BL/6J mice. METHODS Following oral administration of ERV (the same in humans: ×1) or vehicle, daily for three consecutive weeks, temporary focal ischemia was induced by the three vessel occlusion technique. In the other group of animals, after daily ERV (Low: ×1; Med: ×3, or High dose: ×9) or vehicle administration for three weeks, we performed a quantitative assessment of spatial learning or intracerebral BDNF levels. RESULTS The volumes of infarcted lesions, brain edema and the extent of the neurological deficits were significantly reduced in the ERV-treated group. ERV treatment also enhanced spatial learning, accompanied by upregulated BDNF in the cortex. CONCLUSIONS Daily oral intake of ERV, at a clinically relevant dose, protects the brain from ischemic stroke, and also enhances the learning function in normal mice. As millions of people are currently taking the drug safely, and have been for many years in some cases, there is a need to test the inhibitory actions of the drug on progressive dementia encountered in humans with recurrent ischemic attacks or Alzheimer's disease.
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Li M, Armelloni S, Zennaro C, Wei C, Corbelli A, Ikehata M, Berra S, Giardino L, Mattinzoli D, Watanabe S, Agostoni C, Edefonti A, Reiser J, Messa P, Rastaldi MP. BDNF repairs podocyte damage by microRNA-mediated increase of actin polymerization. J Pathol 2015; 235:731-44. [PMID: 25408545 DOI: 10.1002/path.4484] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 10/17/2014] [Accepted: 11/11/2014] [Indexed: 12/24/2022]
Abstract
Idiopathic focal segmental glomerulosclerosis (FSGS) is a progressive and proteinuric kidney disease that starts with podocyte injury. Podocytes cover the external side of the glomerular capillary by a complex web of primary and secondary ramifications. Similar to dendritic spines of neuronal cells, podocyte processes rely on a dynamic actin-based cytoskeletal architecture to maintain shape and function. Brain-derived neurotrophic factor (BDNF) is a pleiotropic neurotrophin that binds to the tropomyosin-related kinase B receptor (TrkB) and has crucial roles in neuron maturation, survival, and activity. In neuronal cultures, exogenously added BDNF increases the number and size of dendritic spines. In animal models, BDNF administration is beneficial in both central and peripheral nervous system disorders. Here we show that BDNF has a TrkB-dependent trophic activity on podocyte cell processes; by affecting microRNA-134 and microRNA-132 signalling, BDNF up-regulates Limk1 translation and phosphorylation, and increases cofilin phosphorylation, which results in actin polymerization. Importantly, BDNF effectively repairs podocyte damage in vitro, and contrasts proteinuria and glomerular lesions in in vivo models of FSGS, opening a potential new perspective to the treatment of podocyte disorders.
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Affiliation(s)
- Min Li
- Renal Research Laboratory, Fondazione D'Amico per la Ricerca sulle Malattie Renali & Fondazione IRCCS Ca', Granda Ospedale Maggiore Policlinico, Milano, Italy
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Sun QQ, Zhang Z, Sun J, Nair AS, Petrus DP, Zhang C. Functional and structural specific roles of activity-driven BDNF within circuits formed by single spiny stellate neurons of the barrel cortex. Front Cell Neurosci 2014; 8:372. [PMID: 25414642 PMCID: PMC4222225 DOI: 10.3389/fncel.2014.00372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 10/21/2014] [Indexed: 11/13/2022] Open
Abstract
Brain derived neurotrophic factor (BDNF) plays key roles in several neurodevelopmental disorders and actions of pharmacological treatments. However, it is unclear how specific BDNF’s effects are on different circuit components. Current studies have largely focused on the role of BDNF in modification of synaptic development. The precise roles of BDNF in the refinement of a functional circuit in vivo remain unclear. Val66Met polymorphism of BDNF may be associated with increased risk for cognitive impairments and is mediated at least in part by activity-dependent trafficking and/or secretion of BDNF. Using mutant mice that lacked activity-driven BDNF expression (bdnf-KIV), we previously reported that experience regulation of the cortical GABAergic network is mediated by activity-driven BDNF expression. Here, we demonstrate that activity-driven BDNF’s effects on circuits formed by the layer IV spiny stellate cells are highly specific. Structurally, dendritic but not axonal morphology was altered in the mutant. Physiologically, GABAergic but not glutamatergic synapses were severely affected. The effects on GABA transmission occurs via presynaptic alteration of calcium-dependent release probability. These results suggest that neuronal activity through activity-driven BDNF expression, can selectively regulate specific features of layer IV circuits in vivo. We postulate that the role of activity-dependent BDNF is to modulate the computational ability of circuits that relate to the gain control (i.e., feed-forward inhibition); whereas the basic wiring of circuits relevant to the sensory pathway is spared. Gain control modulation within cortical circuits has broad impact on cognitive processing and brain state-transitions. Cognitive behavior and mode is determined by brain states, thus the studying of circuit alteration by endogenous BDNF provides insights into the cellular and molecular mechanisms of diseases mediated by BDNF.
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Affiliation(s)
- Qian-Quan Sun
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY USA
| | - Zhi Zhang
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY USA
| | - June Sun
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY USA
| | - Anand S Nair
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY USA
| | - Dan P Petrus
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY USA
| | - Chunzhao Zhang
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY USA
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mTOR and autophagy in normal brain aging and caloric restriction ameliorating age-related cognition deficits. Behav Brain Res 2014; 264:82-90. [DOI: 10.1016/j.bbr.2014.02.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/31/2014] [Accepted: 02/04/2014] [Indexed: 12/15/2022]
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Form follows function: BDNF and its involvement in sculpting the function and structure of synapses. Neuropharmacology 2014; 76 Pt C:628-38. [DOI: 10.1016/j.neuropharm.2013.05.029] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 05/13/2013] [Accepted: 05/15/2013] [Indexed: 12/31/2022]
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Alder J, Kallman S, Palmieri A, Khadim F, Ayer JJ, Kumar S, Tsung K, Grinberg I, Thakker-Varia S. Neuropeptide orphanin FQ inhibits dendritic morphogenesis through activation of RhoA. Dev Neurobiol 2013; 73:769-84. [PMID: 23821558 DOI: 10.1002/dneu.22101] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 12/18/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) plays a facilitatory role in neuronal development and promotion of differentiation. Mechanisms that oppose BDNF's stimulatory effects create balance and regulate dendritic growth. However, these mechanisms have not been studied. We have focused our studies on the BDNF-induced neuropeptide OrphaninFQ/ Nociceptin (OFQ); while BDNF is known to enhance synaptic activity, OFQ has opposite effects on activity, learning, and memory. We have now examined whether OFQ provides a balance to the stimulatory effects of BDNF on neuronal differentiation in the hippocampus. Golgi staining in OFQ knockout (KO) mice revealed an increase in primary dendrite length as well as spine density, suggesting that endogenous OFQ inhibits dendritic morphology. We have also used cultured hippocampal neurons to demonstrate that exogenous OFQ has an inhibitory effect on dendritic growth and that the neuropeptide alters the response to BDNF when pre-administered. To determine if BDNF and OFQ act in a feedback loop, we inhibited the actions of the BDNF and OFQ receptors, TrkB and NOP using ANA-12 and NOP KO mice respectively but our data suggest that the two factors do not act in a negative feedback loop. We found that the inhibition of dendritic morphology induced by OFQ is via enhanced RhoA activity. Finally, we have evidence that RhoA activation is required for the inhibitory effects of OFQ on dendritic morphology. Our results reveal basic mechanisms by which neurons not only regulate the formation of proper dendritic growth during development but also control plasticity in the mature nervous system.
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Affiliation(s)
- Janet Alder
- Department of Neuroscience and Cell Biology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, New Jersey
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Transient domoic acid excitotoxicity increases BDNF expression and activates both MEK- and PKA-dependent neurogenesis in organotypic hippocampal slices. BMC Neurosci 2013; 14:72. [PMID: 23865384 PMCID: PMC3722092 DOI: 10.1186/1471-2202-14-72] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 07/12/2013] [Indexed: 01/24/2023] Open
Abstract
Background We have previously reported evidence of cell proliferation and increased neurogenesis in rat organotypic hippocampal slice cultures (OHSC) after a transient excitotoxic injury to the hippocampal CA1 area induced by low concentrations of the AMPA/kainate agonist domoic acid (DOM). An increased baseline rate of neurogenesis may contribute to recovery from DOM-induced mild injury but the intracellular mechanism(s) responsible for neuronal proliferation remain unclear. The current study investigated the key intracellular pathways responsible for DOM-induced neurogenesis in OHSC including the effects of transient excitotoxicity on the expression of brain-derived neurotrophic factor (BDNF), a well-known regulator of progenitor cell mitosis. Results Application of a low concentration of DOM (2 μM) for 24 h followed by recovery induced a significant and long lasting increase in BDNF protein levels expressed by both neurons and microglial cells. Furthermore, the mild DOM toxicity stimulated both PKA and MEK-dependent intracellular signaling cascades and induced a significant increase in BDNF- transcription factor CREB activation and BDNF-receptor TrkB expression. Coexposure to specific inhibitors of PKA and MEK phosphorylation resulted in a significant decrease in the neurogenic marker doublecortin. Conclusions Our results suggest that transient excitotoxic insult induced by DOM produces BDNF and CREB overexpression via MEK and PKA pathways and that both pathways mediate, at least in part, the increased neural proliferation resulting from mild excitotoxicity.
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Alder J, Kramer BC, Hoskin C, Thakker-Varia S. Brain-derived neurotrophic factor produced by human umbilical tissue-derived cells is required for its effect on hippocampal dendritic differentiation. Dev Neurobiol 2012; 72:755-65. [DOI: 10.1002/dneu.20980] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Neural activity and branching of embryonic retinal ganglion cell dendrites. Mech Dev 2012; 129:125-35. [PMID: 22587886 DOI: 10.1016/j.mod.2012.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 04/24/2012] [Accepted: 05/07/2012] [Indexed: 11/23/2022]
Abstract
The shape of a neuron's dendritic arbor is critical for its function as it determines the number of inputs the neuron can receive and how those inputs are processed. During development, a neuron initiates primary dendrites that branch to form a simple arbor. Subsequently, growth occurs by a process that combines the extension and retraction of existing dendrites, and the addition of new branches. The loss and addition of the fine terminal branches of retinal ganglion cells (RGCs) is dependent on afferent inputs from its synaptic partners, the amacrine and bipolar cells. It is unknown, however, whether neural activity regulates the initiation of primary dendrites and their initial branching. To investigate this, Xenopus laevis RGCs developing in vivo were made to express either a delayed rectifier type voltage-gated potassium (KV) channel, Xenopus Kv1.1, or a human inward rectifying channel, Kir2.1, shown previously to modulate the electrical activity of Xenopus spinal cord neurons. Misexpression of either potassium channel increased the number of branch points and the total length of all the branches. As a result, the total dendritic arbor was bigger than for control green fluorescent protein-expressing RGCs and those ectopically expressing a highly related mutant non-functional Kv1.1 channel. Our data indicate that membrane excitability regulates the earliest differentiation of RGC dendritic arbors.
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Faux C, Rakic S, Andrews W, Britto JM. Neurons on the move: migration and lamination of cortical interneurons. Neurosignals 2012; 20:168-89. [PMID: 22572780 DOI: 10.1159/000334489] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The modulation of cortical activity by GABAergic interneurons is required for normal brain function and is achieved through the immense level of heterogeneity within this neuronal population. Cortical interneurons share a common origin in the ventral telencephalon, yet during the maturation process diverse subtypes are generated that form the characteristic laminar arrangement observed in the adult brain. The long distance tangential and short-range radial migration into the cortical plate is regulated by a combination of intrinsic and extrinsic signalling mechanisms, and a great deal of progress has been made to understand these developmental events. In this review, we will summarize current findings regarding the molecular control of subtype specification and provide a detailed account of the migratory cues influencing interneuron migration and lamination. Furthermore, a dysfunctional GABAergic system is associated with a number of neurological and psychiatric conditions, and some of these may have a developmental aetiology with alterations in interneuron generation and migration. We will discuss the notion of additional sources of interneuron progenitors found in human and non-human primates and illustrate how the disruption of early developmental events can instigate a loss in GABAergic function.
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Affiliation(s)
- Clare Faux
- Centre for Neuroscience, University of Melbourne, Parkville, Vic, Australia
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Kawabata I, Kashiwagi Y, Obashi K, Ohkura M, Nakai J, Wynshaw-Boris A, Yanagawa Y, Okabe S. LIS1-dependent retrograde translocation of excitatory synapses in developing interneuron dendrites. Nat Commun 2012; 3:722. [PMID: 22395613 PMCID: PMC3316883 DOI: 10.1038/ncomms1736] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 02/07/2012] [Indexed: 11/30/2022] Open
Abstract
Synaptic remodelling coordinated with dendritic growth is essential for proper development of neural connections. After establishment of synaptic contacts, synaptic junctions are thought to become stationary and provide fixed anchoring points for further dendritic growth. However, the possibility of active translocation of synapses along dendritic protrusions, to guide the proper arrangement of synaptic distribution, has not yet been fully investigated. Here we show that immature dendrites of γ-aminobutyric acid-positive interneurons form long protrusions and that these protrusions serve as conduits for retrograde translocation of synaptic contacts to the parental dendrites. This translocation process is dependent on microtubules and the activity of LIS1, an essential regulator of dynein-mediated motility. Suppression of this retrograde translocation results in disorganized synaptic patterns on interneuron dendrites. Taken together, these findings suggest the existence of an active microtubule-dependent mechanism for synaptic translocation that helps in the establishment of proper synaptic distribution on dendrites. Maturation of synaptic junctions is important for proper neuronal connections. Using live cell imaging, Okabe et al. show that interneuron dendrites extend filopodia-like projections and use microtubule-dependent retrograde transport to guide proper synaptic distribution on dendrites.
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Affiliation(s)
- Izumi Kawabata
- Department of Cellular Neurobiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Miraucourt LS, da Silva JS, Burgos K, Li J, Abe H, Ruthazer ES, Cline HT. GABA expression and regulation by sensory experience in the developing visual system. PLoS One 2012; 7:e29086. [PMID: 22242157 PMCID: PMC3252287 DOI: 10.1371/journal.pone.0029086] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 11/21/2011] [Indexed: 01/20/2023] Open
Abstract
The developing retinotectal system of the Xenopus laevis tadpole is a model of choice for studying visual experience-dependent circuit maturation in the intact animal. The neurotransmitter gamma-aminobutyric acid (GABA) has been shown to play a critical role in the formation of sensory circuits in this preparation, however a comprehensive neuroanatomical study of GABAergic cell distribution in the developing tadpole has not been conducted. We report a detailed description of the spatial expression of GABA immunoreactivity in the Xenopus laevis tadpole brain at two key developmental stages: stage 40/42 around the onset of retinotectal innervation and stage 47 when the retinotectal circuit supports visually-guided behavior. During this period, GABAergic neurons within specific brain structures appeared to redistribute from clusters of neuronal somata to a sparser, more uniform distribution. Furthermore, we found that GABA levels were regulated by recent sensory experience. Both ELISA measurements of GABA concentration and quantitative analysis of GABA immunoreactivity in tissue sections from the optic tectum show that GABA increased in response to a 4 hr period of enhanced visual stimulation in stage 47 tadpoles. These observations reveal a remarkable degree of adaptability of GABAergic neurons in the developing brain, consistent with their key contributions to circuit development and function.
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Affiliation(s)
- Loïs S. Miraucourt
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Jorge Santos da Silva
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Kasandra Burgos
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
- Stony Brook School of Medicine, Stony Brook University, Stony Brook, New York, United States of America
| | - Jianli Li
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
- Departments of Cell Biology and Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Hikari Abe
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Edward S. Ruthazer
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Hollis T. Cline
- Departments of Cell Biology and Chemical Physiology, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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Green MF, Scott JW, Steel R, Oakhill JS, Kemp BE, Means AR. Ca2+/Calmodulin-dependent protein kinase kinase beta is regulated by multisite phosphorylation. J Biol Chem 2011; 286:28066-79. [PMID: 21669867 PMCID: PMC3151052 DOI: 10.1074/jbc.m111.251504] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Revised: 06/01/2011] [Indexed: 01/04/2023] Open
Abstract
Ca(2+)/calmodulin-dependent protein kinase kinase β (CaMKKβ) is a serine/threonine-directed kinase that is activated following increases in intracellular Ca(2+). CaMKKβ activates Ca(2+)/calmodulin-dependent protein kinase I, Ca(2+)/calmodulin-dependent protein kinase IV, and the AMP-dependent protein kinase in a number of physiological pathways, including learning and memory formation, neuronal differentiation, and regulation of energy balance. Here, we report the novel regulation of CaMKKβ activity by multisite phosphorylation. We identify three phosphorylation sites in the N terminus of CaMKKβ, which regulate its Ca(2+)/calmodulin-independent autonomous activity. We then identify the kinases responsible for these phosphorylations as cyclin-dependent kinase 5 (CDK5) and glycogen synthase kinase 3 (GSK3). In addition to regulation of autonomous activity, we find that phosphorylation of CaMKKβ regulates its half-life. We find that cellular levels of CaMKKβ correlate with CDK5 activity and are regulated developmentally in neurons. Finally, we demonstrate that appropriate phosphorylation of CaMKKβ is critical for its role in neurite development. These results reveal a novel regulatory mechanism for CaMKKβ-dependent signaling cascades.
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Affiliation(s)
- Michelle F. Green
- From the Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710 and
| | - John W. Scott
- the Protein Chemistry and Metabolism Unit, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Rohan Steel
- the Protein Chemistry and Metabolism Unit, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Jonathan S. Oakhill
- the Protein Chemistry and Metabolism Unit, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Bruce E. Kemp
- the Protein Chemistry and Metabolism Unit, St. Vincent's Institute of Medical Research, University of Melbourne, Fitzroy, Victoria 3065, Australia
| | - Anthony R. Means
- From the Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710 and
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A key mechanism underlying sensory experience-dependent maturation of neocortical GABAergic circuits in vivo. Proc Natl Acad Sci U S A 2011; 108:12131-6. [PMID: 21730187 DOI: 10.1073/pnas.1105296108] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mechanisms underlying experience-dependent refinement of cortical connections, especially GABAergic inhibitory circuits, are unknown. By using a line of mutant mice that lack activity-dependent BDNF expression (bdnf-KIV), we show that experience regulation of cortical GABAergic network is mediated by activity-driven BDNF expression. Levels of endogenous BDNF protein in the barrel cortex are strongly regulated by sensory inputs from whiskers. There is a severe alteration of excitation and inhibition balance in the barrel cortex of bdnf-KIV mice as a result of reduced inhibitory but not excitatory conductance. Within the inhibitory circuits, the mutant barrel cortex exhibits significantly reduced levels of GABA release only from the parvalbumin-expressing fast-spiking (FS) interneurons, but not other interneuron subtypes. Postnatal deprivation of sensory inputs markedly decreased perisomatic inhibition selectively from FS cells in wild-type but not bdnf-KIV mice. These results suggest that postnatal experience, through activity-driven BDNF expression, controls cortical development by regulating FS cell-mediated perisomatic inhibition in vivo.
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Bellon A, Krebs MO, Jay TM. Factoring neurotrophins into a neurite-based pathophysiological model of schizophrenia. Prog Neurobiol 2011; 94:77-90. [DOI: 10.1016/j.pneurobio.2011.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 04/05/2011] [Accepted: 04/05/2011] [Indexed: 01/02/2023]
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Kizawa-Ueda M, Ueda A, Kawamura N, Ishikawa T, Mutoh E, Fukuda Y, Shiroki R, Hoshinaga K, Ito S, Asakura K, Mutoh T. Neurotrophin levels in cerebrospinal fluid of adult patients with meningitis and encephalitis. Eur Neurol 2011; 65:138-43. [PMID: 21358203 DOI: 10.1159/000324327] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 01/13/2011] [Indexed: 11/19/2022]
Abstract
BACKGROUND The data on cerebrospinal fluid (CSF) levels of neurotrophins (NTs) in patients with meningoencephalitis are scarce, especially in adult patients. METHODS We measured CSF levels of NTs such as nerve growth factor (NGF), brain-derived neurotrophic factor, and neurotrophin-3 (NT-3) in adult patients with various meningitis (n = 10) and encephalitis (n = 10) in both acute phase and recovery phase and adult control subjects (n = 21) by the enzyme-linked immunosorbent assay for NTs. RESULTS Data show that NGF and NT-3 CSF levels were markedly elevated in the patient group in the acute phase compared with non-neurological controls (p < 0.001 and p < 0.05, respectively) and later returned to the levels of controls. Most intriguingly, we only recognized a significant correlation between NGF and NT-3 CSF levels in the patients in the acute phase. CONCLUSION Such strong correlation of NGF and NT-3 CSF levels strongly suggests that in adult patients, some common regulatory mechanism(s) might be present among various kinds of NTs to cope with central nervous system infection.
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Affiliation(s)
- Madoka Kizawa-Ueda
- Department of Neurology, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Toyoake, Aichi, Japan
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Li H, McDonald W, Parada I, Faria L, Graber K, Takahashi DK, Ma Y, Prince D. Targets for preventing epilepsy following cortical injury. Neurosci Lett 2011; 497:172-6. [PMID: 21354270 DOI: 10.1016/j.neulet.2011.02.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 01/11/2011] [Accepted: 02/15/2011] [Indexed: 01/19/2023]
Abstract
Prophylaxis of posttraumatic epilepsy will require a detailed knowledge of the epileptogenic pathophysiological processes that follow brain injury. Results from studies of experimental models and human epilepsy highlight alterations in GABAergic interneurons and formation of excessive new excitatory synaptic connectivity as prominent targets for prophylactic therapies. Promising laboratory results suggest that it will be possible to experimentally modify these aberrant processes and interfere with epileptogenesis. However, a number of key issues must be addressed before these results can be used to frame clinical antiepileptogenic therapy.
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Affiliation(s)
- Huifang Li
- Epilepsy Research Laboratory, Department of Neurology and Neurological Sciences, Stanford University Sch. of Medicine, 300 Pasteur Dr., Stanford, CA 94305, United States
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Huang Y, Morozov A. Hippocampal deletion of BDNF gene attenuates gamma oscillations in area CA1 by up-regulating 5-HT3 receptor. PLoS One 2011; 6:e16480. [PMID: 21298058 PMCID: PMC3027673 DOI: 10.1371/journal.pone.0016480] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 12/21/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Pyramidal neurons in the hippocampal area CA3 express high levels of BDNF, but how this BDNF contributes to oscillatory properties of hippocampus is unknown. METHODOLOGY/PRINCIPAL FINDINGS Here we examined carbachol-induced gamma oscillations in hippocampal slices lacking BDNF gene in the area CA3. The power of oscillations was reduced in the hippocampal area CA1, which coincided with increases in the expression and activity of 5-HT3 receptor. Pharmacological block of this receptor partially restored power of gamma oscillations in slices from KO mice, but had no effect in slices from WT mice. CONCLUSION/SIGNIFICANCE These data suggest that BDNF facilitates gamma oscillations in the hippocampus by attenuating signaling through 5-HT3 receptor. Thus, BDNF modulates hippocampal oscillations through serotonergic system.
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Affiliation(s)
- Ying Huang
- Unit on Behavioral Genetics, Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Alexei Morozov
- Unit on Behavioral Genetics, Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, United States of America
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Ito W, Chehab M, Thakur S, Li J, Morozov A. BDNF-restricted knockout mice as an animal model for aggression. GENES BRAIN AND BEHAVIOR 2011; 10:365-74. [PMID: 21255268 DOI: 10.1111/j.1601-183x.2010.00676.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mice with global deletion of one brain-derived neurotrophic factor (BDNF) allele or with forebrain-restricted deletion of both alleles show elevated aggression, but this phenotype is accompanied by other behavioral changes, including increases in anxiety and deficits in cognition. Here we performed behavioral characterization of conditional BDNF knockout mice generated using a Cre recombinase driver line, KA1-Cre, which expresses Cre in few areas of brain: highly at hippocampal area CA3 and moderately in dentate gyrus, cerebellum and facial nerve nucleus. The mutant animals exhibited elevated conspecific aggression and social dominance, but did not show changes in anxiety-like behaviors assessed using the elevated plus maze and open field test. There were no changes in depression-like behaviors tested in the forced swim test, but small increase in immobility in the tail suspension test. In cognitive tasks, mutants showed normal social recognition and normal spatial and fear memory, but exhibited a deficit in object recognition. Thus, this knockout can serve as a robust model for BDNF-dependent aggression and object recognition deficiency.
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Affiliation(s)
- W Ito
- Unit on Behavioral Genetics, Laboratory of Molecular Pathophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA.
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Reduced somatostatin in subgenual anterior cingulate cortex in major depression. Neurobiol Dis 2011; 42:116-24. [PMID: 21232602 DOI: 10.1016/j.nbd.2011.01.014] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Accepted: 01/03/2011] [Indexed: 01/01/2023] Open
Abstract
Converging evidence suggests a central role for dysfunction of the subgenual anterior cingulate cortex (sgACC) in the pathophysiology of major depressive disorder (MDD). Underlying mechanisms may include altered GABAergic function. Expression of somatostatin (SST), an inhibitory neuropeptide localized to a subset of GABA neurons, has been shown to be lower in the dorsolateral prefrontal cortex of male MDD subjects. Here, to investigate whether alterations in SST may contribute to sgACC dysfunction in MDD, and whether the alterations display sex-specificity, we measured sgACC SST at the mRNA and precursor peptide levels in a large cohort of subjects with MDD. SST mRNA levels were analyzed by quantitative PCR (qPCR) in the postmortem sgACC from male (n=26) and female (n=25) subjects with MDD and sex-matched subjects with no psychiatric diagnosis (n=51). Prepro-SST protein levels were assessed in a subset of subjects (n=42 pairs) by semi-quantitative Western blot. The mRNA expression of SST was significantly reduced by 38% in female subjects and by 27% in male subjects with MDD. The characteristic age-related decline in SST expression was observed in control (Pearson R=-0.357, p=0.005) but not MDD (R=-0.104, p=0.234) subjects, as low expression was detected across ages in MDD subjects. Protein expression was similarly reduced by 19% in both MDD groups, and findings were more robust in female (p=0.0056) than in males (p=0.0373) compared to respective controls. In conclusion, low SST represents a robust pathological finding in MDD. Specifically, alterations in SST signaling and/or SST-bearing GABA neurons may represent a critical pathophysiological entity that contributes to sgACC dysfunction and that matches to the high female vulnerability to develop MDD.
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Yoon YJ, Gokin AP, Martin-Caraballo M. Pharmacological manipulation of GABA-driven activity in ovo disrupts the development of dendritic morphology but not the maturation of spinal cord network activity. Neural Dev 2010; 5:11. [PMID: 20377848 PMCID: PMC2857860 DOI: 10.1186/1749-8104-5-11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 04/08/2010] [Indexed: 11/11/2022] Open
Abstract
Background In the adult nervous system, GABA acts as a major inhibitory neurotransmitter; however, at early stages of neurodevelopment, GABA receptor activation leads to membrane depolarization and accumulation of [Ca2+]i. The role of excitatory GABAergic neurotransmission in the development of the nervous system is not fully understood. In this study, we investigated the role of excitatory GABA-driven activity in regulating the dendritic morphology and network function in the developing chicken spinal cord. Results Both bicuculline, a GABA receptor antagonist, and muscimol, a GABA agonist, inhibit the generation of spontaneous network activity in the isolated spinal cord at E8 or E10, indicating that altering GABA receptor activation disrupts the generation of spontaneous network activity in the chicken spinal cord. Treatment of chicken embryos with bicuculline or muscimol between E5 and E8 (or between E8 and E10), inhibits the dendritic outgrowth of motoneurons when compared to vehicle-treated embryos. The inhibitory effect of bicuculline or muscimol on the dendritic morphology of motoneurons was likely due to inhibition of GABA-driven network activity since a similar effect was also observed following reduction of network activity by Kir2.1 overexpression in the spinal cord. The inhibitory effect of bicuculline or muscimol was not caused by an adverse effect on cell survival. Surprisingly, chronic treatment of chicken embryos with bicuculline or muscimol has no effect on the shape and duration of the episodes of spontaneous activity, suggesting that maturation of network activity is not altered by disruption of the dendritic outgrowth of motoneurons. Conclusions Taken together, these findings indicate that excitatory GABA receptor activation regulates the maturation of dendritic morphology in the developing spinal cord by an activity-dependent mechanism. However, inhibition of dendritic outgrowth caused by disruption of GABA-driven activity does not alter the maturation of spontaneous electrical activity generated by spinal cord networks, suggesting that compensatory mechanisms can reverse any adverse effect of dendritic morphology on network function.
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Affiliation(s)
- Yone J Yoon
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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